Neuronavigated Focalized Transcranial Direct Current Stimulation Administered During Functional Magnetic Resonance Imaging.

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that allows the modulation of the excitability and plasticity of the human brain. Focalized tDCS setups use specific electrode arrangements to constrain the current flow to circumscribed brain regions. However, the effectiveness of focalized tDCS can be compromised by electrode positioning errors on the scalp, resulting in significant reductions of the current dose reaching the target brain regions for tDCS.

Investigating the neural mechanisms of transcranial direct current stimulation effects on human cognition: current issues and potential solutions.

Transcranial direct current stimulation (tDCS) has been studied extensively for its potential to enhance human cognitive functions in healthy individuals and to treat cognitive impairment in various clinical populations. However, little is known about how tDCS modulates the neural networks supporting cognition and the complex interplay with mediating factors that may explain the frequently observed variability of stimulation effects within and between studies. Moreover, research in this field has been characterized by substantial methodological variability, frequent lack of rigorous experimental control and small sample sizes, thereby limiting the generalizability of findings and translational potential of tDCS.

Electrode positioning errors reduce current dose for focal tDCS set-ups: Evidence from individualized electric field mapping.

Objective: Electrode positioning errors contribute to variability of transcranial direct current stimulation (tDCS) effects. We investigated the impact of electrode positioning errors on current flow for tDCS set-ups with different focality.

Methods: Deviations from planned electrode positions were determined using data acquired in an experimental study (N = 240 datasets) that administered conventional and focal tDCS during magnetic resonance imaging (MRI).

Role of the right anterior insula for the emergence of flow-A combined task-based fMRI activation and connectivity study.

The emergence of flow is a situation of high salience because externally oriented attention on the task and access to resources for goal-directed behavior are enhanced, while internally oriented or self-related cognition is decreased. The right anterior insula has been reported as a causal out-flow hub of the salience resting-state network, orchestrating the engagement of the central executive network (CEN) and the disengagement of the default-mode network (DMN) during a functional challenge. In the present study, we employed a combined task-based activation and connectivity analysis to investigate the role of the right anterior insula during the emergence of flow.

The neural correlates of flow experience explored with transcranial direct current stimulation.

The experience of flow ensues when humans engage in a demanding task while task demands are balanced with the individual's level of skill or ability. Here, we further tested the hypothesis that the medial prefrontal cortex (MPFC) plays a causal role in mediating flow experience using transcranial direct current stimulation (tDCS) to interfere with MPFC's deactivation evoked by a flow paradigm and measured by magnetic resonance (MR)-based perfusion imaging. In a balanced, within-subjects repeated measure design, three treatments of tDCS (sham, anodal, cathodal) were applied in a sample of 22 healthy male participants.